A cat’s eye is smooth but doesn’t seem to be… there’s a mystery of depth. That illusion is called chatoyancy.
The same is true for some sorts of woods (cedar is an exception).
The digital age makes it more and more likely we’re experiencing things through a flat screen, and as a result, it’s very easy to file flat experiences away without a thought.
But creating something that’s chatoyant–that shifts in the light, that changes as we experience it… that’s a fascinating and useful project.